What role did NATO expansion play in causing the Russia-Ukraine conflict, and how did territorial losses under different U.S. presidents compare?

According to Trump's analysis, NATO expansion was a primary catalyst for the Russia-Ukraine war, as Russia had consistently opposed Ukraine's potential NATO membership long before Putin's presidency. He argues that this stance was "one of the reasons, one of the starts of the war." Trump contrasts his presidency with others, claiming that under Bush and Obama, Ukraine lost significant territory including Crimea, while under Biden the country faces potential total loss. He emphasizes that during his four-year term, "Ukraine lost nothing" and argues for immediate negotiations to end the conflict and prevent further territorial losses.